• Title/Summary/Keyword: 빙엄 유동

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A Magnetorheological Polishing System (자기유변유체를 이용한 연마가공 시스템)

  • 김영민;신영재;이응숙;이동주
    • Proceedings of the Korean Society of Machine Tool Engineers Conference
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    • 2003.10a
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    • pp.324-328
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    • 2003
  • The Magnetoeheological fluid has the properties that it's viscosity has dramastic changed under some magnetic fields therefore, Magnetorhlogical fluids has been used for micro polishing of the micro part( for example, a aspherical surface in a micro lens). The polishing process may appears as follows. A part rotating on the spindle is brought into contact with an Magnetorhological finshing(MRF) fluids which is set in motion by the moving wall. In the region where the part and the MRF fulid ate brought into contact, the applied magnetic field creates the conditions necessary for the material removal from the part surface. The material removal takes place in a certain region contacting the surface of the part which can be called the polishing spot or zone. The polishing mechanism of the material removal in the contact zone is considered as a process governed by the particularities of the Bingham flow in the contact zone. Resonable calculated and experimental magnitudes of the material removal rate f3r glass polishing lends support the validity of the approach.

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A Study on the Coating Thickness of Surface Modified Aggregate by Using the Excess Paste Theory and Rheology Value (잉여 페이스트 이론과 레올로지 정수를 이용한 표면 개질골재의 피막두께 평가에 관한 연구)

  • Choi, Hee-Sup;Choi, Hyeong-Gil
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.23 no.5
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    • pp.23-29
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    • 2019
  • This study applies to the surface modification technique by coating the surface of aggregates using the modified paste such as cementitious materials in order to develop completely recycling technology of coarse aggregate. In this case, coating thickness of modified aggregate can be considered that the decision is dependent on the viscosity and tenacity of modified paste. In this study identify the flow properties of the fresh modified paste, and examined for the coating thickness of modified aggregate. As a result, it was possible to design a quantitative coating thickness of modified paste assuming that a modified paste to a Bingham Fluid and consider by excess paste theory and rheology constant (yield value). Accordingly, it is considered that the quantitative mix design of concrete using by surface modified aggregates will be possible.